Analysis of the Alkali Flow in Ironmaking Reactors by a Thermochemical Approach: Blast Furnace. Issue 2 (7th November 2017)

• Record Type: Journal Article
• Authors: Pichler, Anton; Hauzenberger, Franz; Schenk, Johannes; Stocker, Hugo; Thaler, Christoph
• Is Part Of: Steel research international. Volume 89:Issue 2(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-11-07
• Subjects: alkali metals -- blast furnace -- halogens -- ironmaking -- modeling; Steel -- Periodicals; Steel -- Metallurgy -- Periodicals; 669.142
• DOI: 10.1002/srin.201700303
• Languages: English
• ISSNs: 1611-3683

Abstract

Abstract : Elements like potassium and sodium have a negative impact on the blast furnace performance. Therefore, the flow of alkali metals in and out of the reactor has to be controlled. In the furnace, the chemical and physical properties of K and Na lead to the formation of a circulating movement. To point out the characteristics of this alkali‐cycle, a thermochemical model is developed. The program is linked with the databases of Factsage 7.0. Based on a defined standard process, the alkali distribution in particular regions of the reactor is calculated. The results of the calculations show the enrichment of alkalis in the blast furnace, the stability of chosen alkali compounds over the reactor height, and the alkali load in the output flows (slag, metal, and top gas). Furthermore, a modification of the model is done by the addition of halogens (chlorine, fluorine). A significant coherence is observed between the formation of alkali and halogen compounds. The results of the model are compared and confirmed by the validation of investigations on industrial plants. Abstract : Alkalis are generally known as harmful elements for ironmaking processes. To get knowledge about the alkali streams, an alkali model is developed. Connected with an empiric slag zone and a multi stage model, the stable alkali compounds are calculated by a thermochemical program. The alkali‐bearing streams show the distribution and enrichment in specific furnace areas. Additionally, a modification of the model is done to investigate the influence of chlorine and fluorine.